7.1 sound-HELP

I finally got my 7.1 setup hooked up. Problem is--no sound from SB speakers. I first tried multi-channel SACD then put in Gladiator with DTS-ES. Played whole first battle with nothing. I have the Pioner 811 and set the sound to the 7.1 setting. Even when I turned all speaker settings down except the back two--I got nothing. Is there something else I should be doing?

Thanks for the reply. I have all the speakers turned on (just like you Craig--had to go through and do that). As for the amp, I wouldn't think it is something I have to have since the receiver is 7.1 and is a choice setting on everything. Even with the quick set up you have to enter how many speakers you have. Do you think putting it to 5.1 will split the signal like 7.1 actually has to do? Maybe 7.1 speakers is looking for a discrete signal that isn't actually there--just thinking out loud.